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Olech M. The genetic variability of small-ruminant lentiviruses and its impact on tropism, the development of diagnostic tests and vaccines and the effectiveness of control programmes. J Vet Res 2023; 67:479-502. [PMID: 38130459 PMCID: PMC10730557 DOI: 10.2478/jvetres-2023-0064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 11/13/2023] [Indexed: 12/23/2023] Open
Abstract
Introduction Maedi-visna virus and caprine arthritis encephalitis virus are two closely related lentiviruses which cause multisystemic, progressive and persistent infection in goats and sheep. Because these viruses frequently cross the species barrier, they are considered to be one genetic group called small-ruminant lentiviruses (SRLV). They have in vivo tropism mainly for monocytes and macrophages and organ tropism with unknown mechanisms. Typical clinical signs are pneumonia in sheep, arthritis in goats, and mastitis in both species. Infection with SRLV cannot currently be treated or prevented, and control programmes are the only approaches to avoiding its spread. These programmes rely mainly on annual serological testing and elimination of positive animals. However, the high genetic and antigenic variability of SRLV complicate their early and definitive diagnosis. The objective of this review is to summarise the current knowledge of SRLV genetic variation and its implications for tropism, the development of diagnostic tests and vaccines and the effectiveness of control and eradication programmes. Material and Methods Subject literature was selected from the PubMed and the Google Scholar databases. Results The high genetic diversity of SRLV affects the performance of diagnostic tools and therefore control programmes. For the early and definitive diagnosis of SRLV infection, a combination of serological and molecular tests is suggested. Testing by PCR can also be considered for sub-yearling animals. There are still significant gaps in our knowledge of the epidemiology, immunology and biology of SRLV and their impact on animal production and welfare. Conclusion This information may aid selection of the most effective SRLV spread reduction measures.
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Affiliation(s)
- Monika Olech
- Department of Pathology, National Veterinary Research Institute, 24-100Puławy, Poland
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Molossi FA, de Cecco BS, de Almeida BA, Henker LC, da Silva MS, Mósena ACS, Canal CW, Brandalise L, Simão GMR, Vanucci F, Pavarini SP, Driemeier D. PCV3-associated reproductive failure in pig herds in Brazil. Trop Anim Health Prod 2022; 54:293. [PMID: 36097231 DOI: 10.1007/s11250-022-03282-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 08/31/2022] [Indexed: 11/24/2022]
Abstract
Porcine circovirus type 3 (PCV3) has been widely detected worldwide in healthy and sick pigs. Recently its association with clinical disease and reproductive failure has been proven through the detection of intralesional viral mRNA in affected pigs. This study aims to describe the occurrence of PCV3-associated reproductive failure (abortions) in sow herds in southern Brazil. Eleven fetuses from five different litters from two herds were analyzed. These herds reported an increase in the rate of late-gestation abortions, stillbirths, and the percentage of mummified piglets. At gross examination, six of the fetuses had large caudally rotated ears and one fetus was mummified. Microscopically, multisystemic vasculitis, lymphocytic interstitial pneumonia, myocarditis, and encephalitis were observed. These six fetuses with gross and histological lesions were positive in qPCR analysis for PCV3, and PCV3 transcription was shown through in situ hybridization (ISH-RNA) within the histologic lesions. Samples from all 11 fetuses tested negative in PCR exam for Porcine Circovirus type 1 and 2, Porcine Reproductive and Respiratory Syndrome, Porcine Parvovirus, and Atypical Porcine Pestivirus. Furthermore, based on the ORF2 analysis, the PCV3a clade was identified. This is the first report of PCV3a-associated reproductive failure in pig herds in South America.
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Affiliation(s)
- Franciéli Adriane Molossi
- Setor de Patologia Veterinária, Faculdade de Veterinária, Universidade Federal Do Rio Grande Do Sul (UFRGS), Porto Alegre, RS, Brazil.
| | - Bianca Santana de Cecco
- Setor de Patologia Veterinária, Faculdade de Veterinária, Universidade Federal Do Rio Grande Do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Bruno Albuquerque de Almeida
- Setor de Patologia Veterinária, Faculdade de Veterinária, Universidade Federal Do Rio Grande Do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Luan Cleber Henker
- Setor de Patologia Veterinária, Faculdade de Veterinária, Universidade Federal Do Rio Grande Do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Mariana Soares da Silva
- Laboratório de Virologia, Faculdade de Veterinária, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil
| | - Ana Cristina Sbaraini Mósena
- Laboratório de Virologia, Faculdade de Veterinária, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil
| | - Cláudio Wageck Canal
- Laboratório de Virologia, Faculdade de Veterinária, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil
| | | | | | - Fabio Vanucci
- University of Minnesota Veterinary Diagnostic Laboratory, St. Paul, MN, USA
| | - Saulo P Pavarini
- Setor de Patologia Veterinária, Faculdade de Veterinária, Universidade Federal Do Rio Grande Do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - David Driemeier
- Setor de Patologia Veterinária, Faculdade de Veterinária, Universidade Federal Do Rio Grande Do Sul (UFRGS), Porto Alegre, RS, Brazil
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